Gasoline Direct Injection (GDI) engines are becoming commonplace under the hood of modern vehicles. With the fuel injection arrangement of GDI, fuel enters the combustion chamber directly from injectors mounted in the cylinder head, much like a diesel engine, and thus the fuel completely by-passes the air induction system and intake valves during injection.
There are many advantages to gasoline direct injection systems. GDI engines commonly have more power and better fuel economy than multi-port fuel injected engines of similar size and configuration. One of the disadvantages is that deposits will accumulate on the “inlet side” of the intake valve and on the valve stems, due to residual exhaust gasses and crankcase ventilation. These deposits are not amenable to cleaning through the use of conventional fuel detergents since these surfaces are never contacted by fuel as surfaces are in multi-port fuel injection (MPFI) or throttle body injection (TBI) equipped engines. Thus, these deposits build quickly over time and eventually these deposits result in poor engine performance. Currently there is no convenient maintenance procedure to correct this problem. Affected vehicles require significant tear down and mechanical cleaning of the ports and valves. This is a costly operation requiring several hours of labor.
Despite the advantages of gasoline direct injection engines, the lack of a non-invasive and labor intensive maintenance procedure for cleaning engine deposits has made GDI a less desirable approach. Thus, there exists a need for a low cost product and non-invasive method for cleaning and maintaining gasoline direct injection engines.